This application relates to induction heating and particularly to inductive heating of workpieces disposed between inductor turns forming a channel. The invention is more particularly applicable to systems wherein the workpiece is moved by a conveyor through the channel formed by the coil for heating. However, it will be appreciated to those skilled in the art that the invention could be readily adapted for use in other environments as, for example, where similar conductors employed for induction heating can be selectively adjusted and positioned to improve the quality of the inductive heating process of the workpiece.
Conventional induction heating systems have lacked the ability to be conveniently adjustable so that the inductor turns can accommodate a wide variety of different configurations and sizes of workpieces. Typically, a conveyor and workpiece member would be employed to convey the workpiece through a fixed induction heating coil for heating to a desired temperature. In such assemblies, the construction of the coil itself is completely fixed and thereby limited to a part size so that when different parts are sought to be heated by the coil, the coil would have to be disassembled, and reassembled in a different size for more efficient heating of the workpiece.
With particular reference to FIGS. 1A and 1B, a conventional fixed channel coil is shown. The coil 8 is comprised of inductor turns 10, 12, 14, 16 supported by frame members 18, 20. Power is supplied to the turns 12 and 16 via connectors 24, 26 at first end 32 and the circuit is closed at the other end 30 by crossover connectors 34 and 36. Crossover 38 on end 32 connects turns 10 and 14. Of special significance in this structural assembly is that the conductor turns are all supported and attached to fixed frame and connector members. In particular, crossover connectors 34, 36 and 38 comprise rigid structural connections to preclude adjustment of the relative spacing between the turns 10-16 so that after the assembly 8 is constructed, the dimensions of the channel are fixed relative to the length, width and height spacing between the turns. Accordingly, the coil is constructed to accommodate and process a generally single sized workpiece. If the size of the workpiece were to change so that existing coil dimensions are either unacceptable or undesirable, the entire coil must be disassembled and reassembled with connectors of different dimensions to better accommodate the new sized workpiece. Alternatively, a plurality of coils of different dimensions would be serially aligned and only the coil that would best perform the heating job would be operable, but the costs of such an assembly, as well as its overall inefficiency, make such a system highly undesirable.
The subject invention comprises a new and improved adjustable coil assembly that can accommodate quick and easy independent adjustment of coil dimensions such as width and turn spacing to more efficiently meet varying part dimensions or process requirements within a given heating system.